Use of a Three-Dimensional Detailed Modeling Approach for Predicting Root Water Uptake

Javaux et al.

2017-10-25

Why Investigate Root Architecture and Water Uptake?

Theory & History

Root-Soil Water Movement and Solute Model (R-SWMS)

Richard’s Equation


Solving Richard’s Equation

Solving Richard’s Equation Cont.

The Assumptions

  1. Soil water is preferably taken up at spatial locations where the energy to bring water to the root collar is minimized.
  2. Osmotic potential is negligible and root water capacity can be neglected.
    1. Valid under normal conditions. What about water stress?

The Questions


  1. How do collar boundary conditions affect uptake?

  2. How does soil texture affect uptake?

  3. Which model parameters have what affect?

  4. Effective sinusoidal day-night cycle?

Methodology: Scenarios

Table_1

Methodology: Parameters

Table_2

Effects of Soil Type

Fig_1

Reference Parameterization with Collar Boundary Condition 1

Fig_2

Effect of the Parameterization on the Root Collar Flux

Fig_3

Effect of Parameterization on the Three-Dimensional Distribution of Water Content

Fig_4

Effect of Parameterization on the Sink-Term Profiles

Fig_5

Effect of Parameterization on the Vertical Distribution of Water Content and Flow Velocity Field

Fig_6

Effect of Parameterization on the Vertical Distribution of Water Content and Flow Velocity Field Cont.

Fig_7

Effect of Parameterization on the Vertical Distribution of Water Content and Flow Velocity Field Cont. 2

Fig_8

Effect of Soil Type

Fig_9

Effect of Soil Type Cont.

Fig_10

Effect of Soil Type Cont. 2

Fig_11

Day-Night Scenario

Fig_12

Effective Sink Term as a Function of Bulk Water Potential and Averaged Water Content

Fig_13

Effective Sink Term as a Function of Bulk Water Potential and Averaged Water Content Cont.

Fig_14

Conclusions

LaTex Equations

  1. \(y = \beta_1 + \beta_2 x + \varepsilon_1\)
  2. \(\mu = \displaystyle \frac{\sum\limits_{i=0}^n{x_i}}{n}\)
  3. Miscellanious stuff
    1. \(\sqrt{x} \quad \displaystyle \binom{k}{n} \quad \frac{\partial f}{\partial x}\)
    2. \(A \cup B \qquad A \cap B \qquad A \in B\)
    3. \(\Delta \verb/ or / \delta ?\)
    4. \(\displaystyle \int_0^{\infty} f(x) \quad \displaystyle \lim_{x\to\infty}\)

      1. Wow. Look at all that LaTex

References

Dorlodot S, B. Forster, L. Pagès, A. Price, R. Tuberosa, Draye X 2007: Root system architecture: Opportunities and constraints for genetic improvement of crops. Trends in Plant Science, 12, 474–481.

Doussan C., L. Pagès, Vercambre G 1998: Modelling of the hydraulic architecture of root systems: An integrated approach to water absorption—Model description. Annals of Botany, 81, 213–223.

Green S, M.B. Kirkham, Clothier BE 2006: Root uptake and transpiration: From measurements and models to sustainable irrigation. Agricultural Water Management, 86, 165–176.

Somma F, J.W. Hopmans., Clausnitzer V 1998: Transient three-dimensional modeling of soil water and solute transport with simultaneous root growth, root water and nutrient uptake. Plant and Soil, 202, 281–293.